package br.com.winesys.geta.persistence.hibernate;

import java.io.Serializable;
import java.lang.reflect.Method;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Properties;
import org.hibernate.HibernateException;
import org.hibernate.type.NullableType;
import org.hibernate.type.TypeFactory;
import org.hibernate.usertype.ParameterizedType;
import org.hibernate.usertype.UserType;

public class GenericEnumUserType implements UserType, ParameterizedType {

	private static final String DEFAULT_IDENTIFIER_METHOD_NAME = "name";
	private static final String DEFAULT_VALUE_OF_METHOD_NAME = "valueOf";
	private Class<? extends Enum<?>> enumClass;
	private Class<?> identifierType;
	private Method identifierMethod;
	private Method valueOfMethod;
	private NullableType type;
	private int[] sqlTypes;

	@SuppressWarnings("unchecked")
	@Override
	public void setParameterValues(Properties parameters) {
		final String enumClassName = parameters.getProperty("enumClass");
		try {
			this.enumClass = (Class<? extends Enum<?>>) Class.forName(enumClassName).asSubclass(Enum.class);
		} catch (final ClassNotFoundException cfne) {
			throw new HibernateException("Enum class not found", cfne);
		}

		final String identifierMethodName = parameters.getProperty("identifierMethod", GenericEnumUserType.DEFAULT_IDENTIFIER_METHOD_NAME);

		try {
			this.identifierMethod = this.enumClass.getMethod(identifierMethodName, new Class[0]);
			this.identifierType = this.identifierMethod.getReturnType();
		} catch (final Exception e) {
			throw new HibernateException("Failed to obtain identifier method", e);
		}

		this.type = (NullableType) TypeFactory.basic(this.identifierType.getName());

		if (this.type == null) {
			throw new HibernateException("Unsupported identifier type " + this.identifierType.getName());
		}

		this.sqlTypes = new int[] { this.type.sqlType() };

		final String valueOfMethodName = parameters.getProperty("valueOfMethod", GenericEnumUserType.DEFAULT_VALUE_OF_METHOD_NAME);

		try {
			this.valueOfMethod = this.enumClass.getMethod(valueOfMethodName, new Class[] { this.identifierType });
		} catch (final Exception e) {
			throw new HibernateException("Failed to obtain valueOf method", e);
		}
	}

	@Override
	public Class<?> returnedClass() {
		return this.enumClass;
	}

	@Override
	public Object nullSafeGet(ResultSet rs, String[] names, Object owner) throws HibernateException, SQLException {
		final Object identifier = this.type.get(rs, names[0]);
		if (identifier == null) {
			return null;
		}

		try {
			return this.valueOfMethod.invoke(this.enumClass, new Object[] { identifier });
		} catch (final Exception e) {
			throw new HibernateException("Exception while invoking valueOf method '" + this.valueOfMethod.getName() + "' of " + "enumeration class '" + this.enumClass + "'", e);
		}
	}

	@Override
	public void nullSafeSet(PreparedStatement st, Object value, int index) throws HibernateException, SQLException {
		try {
			if (value == null) {
				st.setNull(index, this.type.sqlType());
			} else {
				final Object identifier = this.identifierMethod.invoke(value, new Object[0]);
				this.type.set(st, identifier, index);
			}
		} catch (final Exception e) {
			throw new HibernateException("Exception while invoking identifierMethod '" + this.identifierMethod.getName() + "' of " + "enumeration class '" + this.enumClass + "'", e);
		}
	}

	@Override
	public int[] sqlTypes() {
		return this.sqlTypes;
	}

	@Override
	public Object assemble(Serializable cached, Object owner) throws HibernateException {
		return cached;
	}

	@Override
	public Object deepCopy(Object value) throws HibernateException {
		return value;
	}

	@Override
	public Serializable disassemble(Object value) throws HibernateException {
		return (Serializable) value;
	}

	@Override
	public boolean equals(Object x, Object y) throws HibernateException {
		return x == y;
	}

	@Override
	public int hashCode(Object x) throws HibernateException {
		return x.hashCode();
	}

	@Override
	public boolean isMutable() {
		return false;
	}

	@Override
	public Object replace(Object original, Object target, Object owner) throws HibernateException {
		return original;
	}
}
